The clinical aspect of this project follows the vaccine production and preclinical safety and immunogenicity testing needed to allow an investigational HIV vaccine to into Phase I evaluation in humans. A new Phase I clinical trial, VRC 006 (04-I-0128) was opened to accrual on 7/19/04 by the VRC Clinical Trials Core (CTC) following completion of the regulatory approvals needed from the FDA, IRB and IBC. The CTC enrolled subjects into two sequential dose cohorts in FY04, completing Data and Safety Monitoring Board (DSMB) safety review between dose groups. The study includes administration of vaccine dosages of 10^9,10^10, and 10^11 particle units (PU) of the investigational vaccine. The CTC will perform the required schedule of follow-up visits needed, which will continue through about April 2005.